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Macquarie-Castlereagh catchment

Environmental watering in the catchment in 2013-14

Watering action Status of Commonwealth action
Macquarie Marshes Completed
Lower Macquarie catchment Yet to commence

A summary of Commonwealth environmental watering from previous years in the Macquarie-Castlereagh is included below. For further information about Commonwealth environmental watering in the Macquarie-Castlereagh and the outcomes achieved, please refer to the Commonwealth environmental water Outcomes Reports and Annual Reports.

Planning for 2013-14

Commonwealth environmental water use options 2013-14: Macquarie River Valley identifies potential Commonwealth environmental watering actions for 2013-14. Decisions on using Commonwealth environmental water will be made throughout the year based on seasonal, operational and management considerations. If you wish to provide suggestions for Commonwealth environmental water use please contact us at ewater@environment.gov.au or send us your suggestion by visiting: Your suggestions for potential water use options.

Water availability and portfolio management

Macquarie-Castlereagh water holdings* at 31 July 2014
Security Registered entitlements (ML) Long Term Average Annual Yield (ML) Carryover from 2013-14 (ML) New allocations in 2014-15 (ML) Available water transferred for delivery or delivered directly in 2014-15 (ML) Estimated current Commonwealth water account balance (ML)
General 122,093 51,279 19,337 - - 19,337
Supplementary 6,292 1,321
Total 128,385 52,600 19,337 - - 19,337

* Macquarie/Cudgegong

Subject to water accounting adjustments. Slight discrepancies may exist due to rounding. Allocations of water against entitlements held in regulated systems are made periodically and will depend on factors including seasonal inflows and rules associated with water accounts. For the purposes of the above table, against supplementary entitlements, no 'carryover' or 'water account balance' is reported, and 'new allocations' and 'available water transferred for delivery or delivered directly' are accounted at the time of take.

For more information regarding the characteristics of entitlements and the water resource plan held in the Macquarie-Castlereagh catchment please refer to New South Wales Department of Primary Industries Office of Water

Water trading

Information on future trade considerations is available at: Portfolio Management Update

Information on current trading actions is available at: Current Trading Actions

Information on previous trading actions is available at: Trading Outcomes

Environmental watering in the catchment in previous years

Environmental watering in the catchment in 2012-13
Watering action Amount of water delivered (ML)
Macquarie River and Marshes 100 000
Total in 2012-13 100 000
Environmental watering in the catchment in 2011-12
Watering action Amount of water delivered (ML)
Macquarie Marshes 35 000
Macquarie Marshes 5 000
Total in 2011-12 40 000
Environmental watering in the catchment in 2010-11
Watering action Amount of water delivered (ML)
Macquarie Marshes 1 888
Macquarie Marshes 25 000
Total in 2010-11 26 888

Catchment profile

Where is it?

The Macquarie Marshes during October 2010. Photo: Simon Banks, CEWO

The Macquarie-Castlereagh catchment is situated in central western NSW and is based around the Castlereagh, Macquarie and Bogan River valleys. The catchment rises near Oberon on the western side of the Great Dividing Range and flowing to the Barwon River near Carinda. The catchment is flanked by the Barwon-Darling catchment to the north and west, the Lachlan to the south and the Namoi to the north.

The Macquarie-Castlereagh catchment covers 91,985km2 (or 8.8 per cent of the MDB area) and contains two major storages, Windamere Dam (capacity 368 GL) on the Cudgegong River and Burrendong Dam (capacity 1,188 GL) on the Macquarie. There are several distributary rivers and creeks that enter the Macquarie river, including Bell, Little and Talbragar Rivers. The landscape of the Macquarie-Castlereagh region varies markedly from east to west and grades from the headwaters (or tablelands) to plains in the west. The Ramsar-listed Macquarie Marshes are located in the far west of the catchment. Since the construction of the Burrendong Dam in 1967, the Macquarie Marshes have declined significantly in health, as it has caused a significant change to natural water flows in the system and specifically to the Marshes.

Northern Catchments page

Legend

red irregular shaped area  denotes ramsar site
Ramsar site

yellow irregular shaped area denotes diwa site
DIWA site

Macquarie-Castlereagh Catchment

What makes this place so special?

The Macquarie-Castlereagh catchment is an ecologically significant area because it includes:

  • wetlands of international significance listed under the Ramsar Convention
  • other flow-dependent assets including the Macquarie River channel, the Lower Macquarie River, and the Effluent Creeks (e.g. Marra Creek, Crooked Creek and Duck Creek) on the western side of the Marshes
  • a diverse range of vegetation including river red gum forest and woodland, black box woodland and lignum
  • migratory bird habitats

The region contains one of the largest and most important wetlands in the Murray-Darling Basin, the Macquarie Marshes. Approximately 200,000 hectares of the Marshes have been listed as nationally important in the Directory of Important Wetlands in Australia (DIWA), while some 18,700 hectares of the Macquarie Marshes has also been listed under the Ramsar convention. The Ramsar listing consists of three separate reserve areas: the Northern Marsh, Southern Marsh and Eastern Marsh.

The Macquarie Marshes contain a wide range of vegetation types, determined by the frequency and duration of flooding. These include river red gum woodland, water couch grasslands, extensive beds of common reed, coolabah, black box, lignum, reed swamp, cumbungi and river cooba.

The range of vegetation found throughout the wetlands provides habitat for many species including 211 bird species (including four waterbird species listed as threatened in NSW), eight species of native mammal, 15 frog species, 56 reptile species and 24 native fish species. Seventeen waterbird species of the Marshes, including the black-tailed godwit and fork-tailed swift, are listed on the JAMBA, CAMBA and/or RoKAMBA international migratory bird agreements.

What does the latest science say about the ecological health of the catchment?

The Sustainable Rivers Audit (SRA), coordinated by the Murray-Darling Basin Authority, provides scientifically robust assessments of the ecological health of the Basin's river valleys. The overall ecosystem health of the Macquarie Valley catchment as reported by the SRA is summarised below.

SRA Report Overall ecosystem health of catchment
SRA 1 (based on data collected from 2004 to 2007) Very poor
SRA 2 (based on data collected from 2008 to 2010) Very poor

The CSIRO Sustainable Yields Report on the Macquarie Valley Catchment indicated that the current level of surface water extraction in the Macquarie valley (excluding the Castlereagh and Bogan Rivers) is moderately high, with 27 per cent of average available water being diverted for use.

While the upper reaches of the Bogan and Castlereagh Rivers are largely unregulated, the Macquarie River is highly regulated. River regulation and water extraction has had substantial effects on flow regimes, with changes to seasonal flow patterns, reduced variability and changes to flood intensity. The average period between significant flood events for the Macquarie Marshes has increased by 114 per cent. The average volume of these floods has also been reduced.

The average period between large flood events for the Macquarie Marshes has increased by 114 per cent. The average volume of these large floods has also been reduced.

Under the best estimate 2030 climate conditions, average surface water availability would be reduced by 8 per cent and end-of-system flows would be reduced by 9 per cent.

It should be noted that the boundaries of this catchment as defined by the Sustainable Yields report differ slightly to the area defined at the top of this page.